package cn.edu.sdjzu.xg.bysj.controller.basic;

import cn.edu.sdjzu.xg.bysj.domain.School;
import cn.edu.sdjzu.xg.bysj.domain.Student;
import cn.edu.sdjzu.xg.bysj.domain.Teacher;
import cn.edu.sdjzu.xg.bysj.service.SchoolService;
import cn.edu.sdjzu.xg.bysj.service.StudentService;
import cn.edu.sdjzu.xg.bysj.service.TeacherService;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializerFeature;
import lombok.extern.slf4j.Slf4j;
import test.BysjException;
import util.Condition;
import util.ControllerHelper;
import util.JSONUtil;
import util.Pagination;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Collection;
import java.util.List;
@Slf4j
@WebServlet("/student.ctl")
public class StudentController extends HttpServlet{
    /**
     * GET, http://localhost:8080/student.ctl?id=1, 查询id=1的学生
     * GET, http://localhost:8080/student.ctl, 查询所有的学生
     * 把一个或所有学生对象响应到前端
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */

    @Override
    protected void doGet(HttpServletRequest request,
                         HttpServletResponse response)
            throws ServletException, IOException {
        //创建JSON对象respMessage_jsonObj，以便往前端响应信息
        JSONObject respMessage_jsonObj = new JSONObject();

        //将request body转换为JSON字串
        String req_jsonStr = JSONUtil.getJSON(request);
        //将request body解析为JSONObject对象
        JSONObject req_jsonObj = JSON.parseObject(req_jsonStr);
        //如果请求body为空
        if (req_jsonObj == null) {
            respMessage_jsonObj.put("message","未收到请求信息！");
            response.getWriter().println(respMessage_jsonObj);
            return;
        }
        //从JSONObject对象中读取键“id”的值（Java Object对象），req_jsonObj可能是{"id":1}
        Object id_obj = req_jsonObj.get("id");
        //Object teacher_obj = req_jsonObj.get("teacherId");
        try {

            //如果id_Obj != null, 说明请求数据有id键，是请求某个学生对象
            if (id_obj != null) {
                int id_int = Integer.parseInt(id_obj.toString());
                responseStudent(id_int, response);
            }
//            else if(teacher_obj!=null){
//                int teacherId_int = Integer.parseInt(teacher_obj.toString());
//                Teacher teacher =TeacherService.getInstance().find(teacherId_int);
//                Pagination pagination = ControllerHelper.getPagination(req_jsonObj);
//                responseStudent_t(response, teacher, pagination);
     //       }
        else {//请求中包含条件和分页信息，需要响应多个学生对象
                //读取分页信息，形成分页对象
                //从JSONObject对象中读取 “pagination” 键对应的值(JSONObject对象)
                Pagination pagination = ControllerHelper.getPagination(req_jsonObj);
                //从请求JSONObject对象中读取键“conditionList”对应的值(描述查询条件的JSONArray对象)
                List<Condition> conditionList = ControllerHelper.getConditions(req_jsonObj);
                //响应多个学生信息，其中conditionList, pagination两个对象引用为空是可能的
                this.responseStudents(response, conditionList, pagination);
            }
        } catch (SQLException e) {
            respMessage_jsonObj.put("message", "数据库操作异常");

            //响应respMessage_jsonObj到前端
            response.getWriter().println(respMessage_jsonObj);
            //打印异常栈，方便调试
            log.trace(e.getMessage());
        } catch (Exception e) {
            respMessage_jsonObj.put("message", "网络异常");
            //响应respMessage_jsonObj到前端
            response.getWriter().println(respMessage_jsonObj);
            //打印异常栈，方便调试
            e.printStackTrace();
        }
    }

    //按分页信息响应符合条件的教师对象和对象总数
    private void responseStudents(HttpServletResponse response,
                                  List<Condition> conditionList_json_str,
                                  Pagination pagination)
            throws ServletException, IOException, SQLException {
        //分页获得满足条件的所有学生
        Collection<Student> students = StudentService.getInstance()
                .findAll(conditionList_json_str, pagination);
        //第二个参数可以防止循环引用
        String students_jsonStr = JSON.toJSONString(students,
                SerializerFeature.DisableCircularReferenceDetect);
        //创建JSON对象resp_jsonObj，以便往前端响应综合信息
        JSONObject resp_jsonObj = new JSONObject();
        resp_jsonObj.put("totalNum", pagination.getTotalNum());
        resp_jsonObj.put("data", students_jsonStr);
        //响应resp_jsonObj到前端
        response.getWriter().println(resp_jsonObj);
    }
    private void responseStudent_t(HttpServletResponse response,Teacher teacher,

                                  Pagination pagination)
            throws ServletException, IOException, SQLException {
        //分页获得满足条件的所有学生
        Collection<Student> students = StudentService.getInstance()
                .findAll(teacher, pagination);
        //第二个参数可以防止循环引用
        String students_jsonStr = JSON.toJSONString(students,
                SerializerFeature.DisableCircularReferenceDetect);
        //创建JSON对象resp_jsonObj，以便往前端响应综合信息
        JSONObject resp_jsonObj = new JSONObject();
        resp_jsonObj.put("totalNum", pagination.getTotalNum());
        resp_jsonObj.put("data", students_jsonStr);
        //响应resp_jsonObj到前端
        response.getWriter().println(resp_jsonObj);
    }
    //响应一个教师对象
    private void responseStudent(int id, HttpServletResponse response)
            throws ServletException, IOException, SQLException {
        //根据id查找学生
        Student student = StudentService.getInstance().find(id);
        String student_jsonStr = JSON.toJSONString(student);
        //响应student_jsonStr到前端
        response.getWriter().println(student_jsonStr);
    }

    /**
     * POST, http://localhost:8080/student.ctl, 增加学生
     * 增加一个学生对象：将来自前端请求的JSON对象，增加到数据库表中
     *
     * @param request  请求对象
     * @param response 响应对象
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String req_studentToAdd_jsonStr = JSONUtil.getJSON(request);
               Student studentToAdd = JSON.parseObject(req_studentToAdd_jsonStr,
                               Student.class);
                JSONObject respMessage_jsonObj = new JSONObject();
               try {
                         StudentService.getInstance().add(studentToAdd);
                       respMessage_jsonObj.put("message", "增加成功");
                    } catch (SQLException e) {
                       respMessage_jsonObj.put("message", "数据库操作异常");
                         log.debug(e.getMessage());
               } catch (BysjException e) {
                   respMessage_jsonObj.put("message", e.getMessage());

                   } catch (Exception e) {
                       respMessage_jsonObj.put("message", "网络异常");
                      log.debug(e.getMessage());
                  }
                response.getWriter().println(respMessage_jsonObj);
           }


    /**
     * DELETE, http://localhost:8080/teacher.ctl, 删除id=1的学生
     * 删除一个学生对象：根据来自前端请求的id，删除数据库表中id的对应记录
     *
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doDelete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //将request参数转换为JSON字串
        String request_json_str = JSONUtil.getJSON(request);
        //将请求body解析为要删除的Teacher的id对应的JSONObject对象(可能是{"id":1})
        JSONObject idOfTeacherToDelete_jsonObj = JSON.parseObject(request_json_str);
        //从JSONObject对象中读取键“id”的值（Java Object对象），
        Object id_obj = idOfTeacherToDelete_jsonObj.get("id");
        int id_int = Integer.parseInt(id_obj.toString());

        //创建JSON对象respMessage_jsonObj，以便往前端响应信息
        JSONObject respMessage_jsonObj = new JSONObject();
        try {
            //到数据库表中删除对应的学生
            StudentService.getInstance().delete(id_int);
            respMessage_jsonObj.put("message", "删除成功");
            log.trace("删除成功");
        } catch (SQLException e) {
            respMessage_jsonObj.put("message", "数据库操作异常");
            //打印异常栈，方便调试（要用log4j代替）
            log.trace(e.getMessage());
        } catch (Exception e) {
            respMessage_jsonObj.put("message", "网络异常");
            //打印异常栈，方便调试（要用log4j代替）
            log.trace(e.getMessage());
        }
        //响应respMessage_jsonObj到前端
        response.getWriter().println(respMessage_jsonObj);
    }


    /**
     * PUT, http://localhost:8080/student.ctl, 修改学生
     * <p>
     * 修改一个学生对象：将来自前端请求的JSON对象，更新数据库表中相同id的记录
     *
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    @Override
    protected void doPut(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String studentToUpdate_jsonStr = JSONUtil.getJSON(request);
        int teacherId =JSON.parseObject(studentToUpdate_jsonStr).getInteger("teacherId");
        Student studentToupdate = JSON.parseObject(studentToUpdate_jsonStr,
                Student.class);
        JSONObject respMessage_jsonObj = new JSONObject();
        try {
            Teacher teacher = TeacherService.getInstance().find(teacherId);
            studentToupdate.setSupervisor(teacher);
            StudentService.getInstance().update(studentToupdate);
            respMessage_jsonObj.put("message", "修改成功");
        } catch (SQLException e) {
            respMessage_jsonObj.put("message", "数据库操作异常");
            //打印异常栈，方便调试（要用log4j代替）
            log.trace(e.getMessage());
        } catch (Exception e) {
            respMessage_jsonObj.put("message", "网络异常");
            //打印异常栈，方便调试（要用log4j代替）
            log.trace(e.getMessage());
        }
        //响应respMessage_jsonObj到前端
        response.getWriter().println(respMessage_jsonObj);
    }
}
